GPS/GIS Mapping Zooms in on OOM IN ON THE FINE DETAIL. Zoom out on the broad sp an. Satellite With the convergence of three well-established techn olo­ gies, satellite imagery, Global Position ing Systems (G PS), and geographic in fonnation systems (GIS), remote sensing is quickly moving frorn an abstract art to high realism. Imagery ZGPSIGIS mapping now takes satellite imagery directly into the field, greatly extending its value and uses for applications as di verse as envi­ ronmemal monitoring. precision farming. and measuring urban sprawl. Sciemists who rely on raw satellite imagery to provide broad brush By Suzanne Richardson strokes of planetary phenomena can now bring th at same imagery down to earLh to create detailed and high ly accurate base map products. Complete GPSIGIS fi eld mapping systems. such as the patented GeoLink Mapping System from GeoResearch Inc .. feature full sc reen rasler or vector background map capability that can accurately register background maps through known control points. Satellite imagery, such as Lh ose from SPOT Image Corp.. can be registered and brought into the field as a background coverage. Other vector layers of infomlation, such as a visual trace of the user's path or mul tiple GIS fil es may be overlaid on the satellite image for further efficiency in the fi eld. GPS/GIS mapping technology uses GPS data to continuously pin­ point position and create an accurate digital map of the user 's pmh. Using small, li ghtweight, pen-based computers. field mapping personnel can quickly elller multiple layers of attribute data describing elIcit point, while watching their GIS maps evolve on the screen. GIS translation functions wi thin GeoLink instantly create spatial infonnation layers for GIS data­ bases. Advanced GPS/GIS systems may also offer GPS integration with other fonns of data, such as data from electronic sensors (temperature, depth. radiation, etc.) to automatically map almost any phenomena. Ground-based digital or video images may also be associated with posi­ tion to creme a visual reference library of the features mapped. The ability to use satell ite im agery for field investigations promises to dramati call y enhance the producti on of maps in many areas of the world, where map sources tend to be outdated, inaccurate, or completely nonexistent. Field mapping personnel now have the advantage of an up­ to-date map reference on which to ret.:ord detailed, geographically correct, feature information. Once in the field , the satellite image provides sever­ al invalu able fu nctions. First it is a visual reference against which GPS­ collected di.lla is displayed; second it is a field guide indicati ng areas for invesli gation; and Lhird. and perhaps mosl importantly, it is a ba<.:kdrop or geographic glue for an entire GIS database. Tom Lyman of GeoResearch Inc. conducts GeoLink® GPS/GIS mapping with satellite imagery has been lI se d in Moscow, GPS/GIS mapping in Moscow. St. Basila Cathedral is Russia. Extensive GPS/GIS fi eld data describing bridges und infrastmc­ seen in the background. lure were collected for business analysis and development. When it came EARTH OliSERVAT10N MAGAZINE September 1995 time to display the infonnalion, no local map sources were avail­ able. Up-to-date sate lli te imagery filled the bill very nicely. GeoResearch Inc. is currently participating in a major study of environmental influences on the shell fish production and aquacul­ ture in the Laguna di Venezia, Italy, using tl,e GeoLink GPS/GIS with satellite imagery. SPOT satellite images used for anal ysis of water temperature , phytoplankton concentrations, eutrophication , and potential so il erosion are being combin ed with detail ed GeoLink GPS/GIS data collected in the sprawling estuary. SPOT imagery combi ned with GeoLink is providing an excellent tool for investigating the obliq ue waters of the estuary's ecosystem. The combined use of the two tech nologies allows rapid assessment of up-to-the-minute aquatic and environmental conditions. The advan tages of satellite imagery - its currency, its impar­ tial coverage of the entire globe and its affordabi lity - are making it Satellite image of the 1993 MISSissippi River flood with a GPS/GIS background map of choice for large parts of the world. GeoLink"/GPS position and attribute data overlaid. Symbols When combined with the ground trutlled specificity of GPS/GIS shown in red indicate structures mapped, using GeoLink", as field mapping, it is promising to open a whole new world of appli­ a result of flood damage (also shown on previous page). cations for satellite imagery. Satellite Image courtesy of SPOT Imago Corp. MORE INFO About the author: GeoResearch, In c. SPOT Image Corp. Suzanne Richardson is a writer and communications specialist at 7913 MacArthur Blvd. 1897 Preston White Drive GeoResearch Inc. She has authored numerous articles on GPS/GIS P.O. Box 220 Reston, VA 22091-4368 applicatio ns and is consulted frequenL1y on the integration and many Cabin John. MD 20818 Telephone: 703-620-2200 uses of GPS/GIS technology. She may be reached at 301-320-0911 . Telephone: 301-320-0911 Fax: 703-648-1 813 mil Fax: 301-320-0922 S POT IMAGE SPOT Image Corporation GeoResearch, Inc. 1897 Preston White Drive 115 North Broadway Reston, VA 22091-4368 Billings, Montana 59101 USA Phone: (406) 248-6771 Tel: 703-715- 3100 Fax: (406) 248-6770 Fax:703-648-1813 email: [email protected] 7913 MacArthur Boulevard P.O. Box 220 Cabin John, Maryland 20818 Phone: (301) 320-09Jl Fax: (301) 320-0922 email: [email protected] EARll-' OOSERVATION MAGAZINE Scplcmbcr 1995 .